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아마존에서 Amazon Ion 데이터 유형 사용하기 QLDB
중요
지원 종료 알림: 기존 고객은 2025년 7월 31일 지원이 종료될 QLDB 때까지 Amazon을 사용할 수 있습니다. 자세한 내용은 아마존 QLDB 원장을 Amazon Aurora SQL Postgre로 마이그레이션을
아마존은 데이터를 아마존 이온 형식으로 QLDB 저장합니다. 에서 QLDB 데이터를 사용하려면 지원되는 프로그래밍 언어에 대한 종속 항목으로 Ion 라이브러리를
이 섹션에서는 데이터를 네이티브 타입에서 해당 타입의 Ion 형식으로 변환하는 방법과 그 반대의 방법을 알아봅니다. 이 참조 안내서는 QLDB 드라이버를 사용하여 QLDB 원장의 Ion 데이터를 처리하는 코드 예제를 보여줍니다. 여기에는 Java, 의 코드 예제가 포함되어 있습니다. NET(C#), Go, Node.js (TypeScript), Python
사전 조건
다음 코드 예제는 이름이 지정된 활성 원장에 연결된 QLDB 드라이버 인스턴스가 있다고 가정합니다. ExampleTable
이 표에는 다음과 같은 8개 필드가 있는 기존 문서 하나가 포함되어 있습니다:
-
ExampleBool
-
ExampleInt
-
ExampleFloat
-
ExampleDecimal
-
ExampleTimestamp
-
ExampleString
-
ExampleBlob
-
ExampleList
참고
이 참조에서는 각 필드에 저장된 형식이 해당 명칭과 일치한다고 가정합니다. 실제로 는 문서 필드에 스키마 또는 데이터 유형 정의를 적용하지 QLDB 않습니다.
부울
다음 코드 예에서는 Ion 부울 타입을 처리하는 방법을 보여줍니다.
- Java
-
// Instantiate an IonSystem from the Ion library IonSystem ionSystem = IonSystemBuilder.standard().build(); boolean exampleBoolean = driver.execute((txn) -> { // Transforming a Java boolean to Ion boolean aBoolean = true; IonValue ionBool = ionSystem.newBool(aBoolean); // Insertion into QLDB txn.execute("UPDATE ExampleTable SET ExampleBool = ?", ionBool); // Fetching from QLDB Result result = txn.execute("SELECT VALUE ExampleBool from ExampleTable"); // Assume there is only one document in ExampleTable for (IonValue ionValue : result) { // Transforming Ion to a Java boolean // Cast IonValue to IonBool first aBoolean = ((IonBool)ionValue).booleanValue(); } // exampleBoolean is now the value fetched from QLDB return aBoolean; });
- .NET
-
using IAsyncResult = Amazon.QLDB.Driver.IAsyncResult; ... IValueFactory valueFactory = new ValueFactory(); // Transforming a C# bool to Ion. bool nativeBool = true; IIonValue ionBool = valueFactory.NewBool(nativeBool); IAsyncResult selectResult = await driver.Execute(async txn => { // Insertion into QLDB. await txn.Execute("UPDATE ExampleTable SET ExampleBool = ?", ionBool); // Fetching from QLDB. return await txn.Execute("SELECT VALUE ExampleBool from ExampleTable"); }); bool? retrievedBool = null; // Assume there is only one document in ExampleTable. await foreach (IIonValue ionValue in selectResult) { // Transforming Ion to a C# bool. retrievedBool = ionValue.BoolValue; }
참고
동기 코드로 변환하려면
await
및async
키워드를 제거하고IAsyncResult
유형을IResult
로 변경하세요. - Go
-
exampleBool, err := driver.Execute(context.Background(), func(txn qldbdriver.Transaction) (interface{}, error) { aBool := true // Insertion into QLDB _, err = txn.Execute("UPDATE ExampleTable SET ExampleBool = ?", aBool) if err != nil { return nil, err } // Fetching from QLDB result, err := txn.Execute("SELECT VALUE ExampleBool FROM ExampleTable") if err != nil { return nil, err } // Assume there is only one document in ExampleTable if result.Next(txn) { var decodedResult bool err := ion.Unmarshal(result.GetCurrentData(), &decodedResult) if err != nil { return nil, err } // exampleBool is now the value fetched from QLDB return decodedResult, nil } return nil, result.Err() })
- Node.js
-
async function queryIonBoolean(driver: QldbDriver): Promise<boolean> { return (driver.executeLambda(async (txn: TransactionExecutor) => { // Updating QLDB await txn.execute("UPDATE ExampleTable SET ExampleBool = ?", true); // Fetching from QLDB const resultList: dom.Value[] = (await txn.execute("SELECT VALUE ExampleBool FROM ExampleTable")).getResultList(); // Assume there is only one document in ExampleTable const ionValue: dom.Value = resultList[0]; // Transforming Ion to a TypeScript Boolean const boolValue: boolean = ionValue.booleanValue(); return boolValue; }) ); }
- Python
-
def update_and_query_ion_bool(txn): # QLDB can take in a Python bool a_bool = True # Insertion into QLDB txn.execute_statement("UPDATE ExampleTable SET ExampleBool = ?", a_bool) # Fetching from QLDB cursor = txn.execute_statement("SELECT VALUE ExampleBool FROM ExampleTable") # Assume there is only one document in ExampleTable for ion_value in cursor: # Ion Python bool is a child class of Python bool a_bool = ion_value # example_bool is now the value fetched from QLDB return a_bool example_bool = driver.execute_lambda(lambda txn: update_and_query_ion_bool(txn))
정수
다음 코드 예에서는 Ion 정수형을 처리하는 방법을 보여줍니다.
- Java
-
// Instantiate an IonSystem from the Ion library IonSystem ionSystem = IonSystemBuilder.standard().build(); int exampleInt = driver.execute((txn) -> { // Transforming a Java int to Ion int aInt = 256; IonValue ionInt = ionSystem.newInt(aInt); // Insertion into QLDB txn.execute("UPDATE ExampleTable SET ExampleInt = ?", ionInt); // Fetching from QLDB Result result = txn.execute("SELECT VALUE ExampleInt from ExampleTable"); // Assume there is only one document in ExampleTable for (IonValue ionValue : result) { // Transforming Ion to a Java int // Cast IonValue to IonInt first aInt = ((IonInt)ionValue).intValue(); } // exampleInt is now the value fetched from QLDB return aInt; });
- .NET
-
using IAsyncResult = Amazon.QLDB.Driver.IAsyncResult; ... IValueFactory valueFactory = new ValueFactory(); // Transforming a C# int to Ion. int nativeInt = 256; IIonValue ionInt = valueFactory.NewInt(nativeInt); IAsyncResult selectResult = await driver.Execute(async txn => { // Insertion into QLDB. await txn.Execute("UPDATE ExampleTable SET ExampleInt = ?", ionInt); // Fetching from QLDB. return await txn.Execute("SELECT VALUE ExampleInt from ExampleTable"); }); int? retrievedInt = null; // Assume there is only one document in ExampleTable. await foreach (IIonValue ionValue in selectResult) { // Transforming Ion to a C# int. retrievedInt = ionValue.IntValue; }
참고
동기 코드로 변환하려면
await
및async
키워드를 제거하고IAsyncResult
유형을IResult
로 변경하세요. - Go
-
exampleInt, err := driver.Execute(context.Background(), func(txn qldbdriver.Transaction) (interface{}, error) { aInt := 256 // Insertion into QLDB _, err = txn.Execute("UPDATE ExampleTable SET ExampleInt = ?", aInt) if err != nil { return nil, err } // Fetching from QLDB result, err := txn.Execute("SELECT VALUE ExampleInt FROM ExampleTable") if err != nil { return nil, err } // Assume there is only one document in ExampleTable if result.Next(txn) { var decodedResult int err := ion.Unmarshal(result.GetCurrentData(), &decodedResult) if err != nil { return nil, err } // exampleInt is now the value fetched from QLDB return decodedResult, nil } return nil, result.Err() })
- Node.js
-
async function queryIonInt(driver: QldbDriver): Promise<number> { return (driver.executeLambda(async (txn: TransactionExecutor) => { // Updating QLDB await txn.execute("UPDATE ExampleTable SET ExampleInt = ?", 256); // Fetching from QLDB const resultList: dom.Value[] = (await txn.execute("SELECT VALUE ExampleInt FROM ExampleTable")).getResultList(); // Assume there is only one document in ExampleTable const ionValue: dom.Value = resultList[0]; // Transforming Ion to a TypeScript Number const intValue: number = ionValue.numberValue(); return intValue; }) ); }
- Python
-
def update_and_query_ion_int(txn): # QLDB can take in a Python int a_int = 256 # Insertion into QLDB txn.execute_statement("UPDATE ExampleTable SET ExampleInt = ?", a_int) # Fetching from QLDB cursor = txn.execute_statement("SELECT VALUE ExampleInt FROM ExampleTable") # Assume there is only one document in ExampleTable for ion_value in cursor: # Ion Python int is a child class of Python int a_int = ion_value # example_int is now the value fetched from QLDB return a_int example_int = driver.execute_lambda(lambda txn: update_and_query_ion_int(txn))
Float
다음 코드 예에서는 Ion 플로트 타입을 처리하는 방법을 보여줍니다.
- Java
-
// Instantiate an IonSystem from the Ion library IonSystem ionSystem = IonSystemBuilder.standard().build(); float exampleFloat = driver.execute((txn) -> { // Transforming a Java float to Ion float aFloat = 256; IonValue ionFloat = ionSystem.newFloat(aFloat); // Insertion into QLDB txn.execute("UPDATE ExampleTable SET ExampleFloat = ?", ionFloat); // Fetching from QLDB Result result = txn.execute("SELECT VALUE ExampleFloat from ExampleTable"); // Assume there is only one document in ExampleTable for (IonValue ionValue : result) { // Transforming Ion to a Java float // Cast IonValue to IonFloat first aFloat = ((IonFloat)ionValue).floatValue(); } // exampleFloat is now the value fetched from QLDB return aFloat; });
- .NET
-
C# 플로트 사용
using IAsyncResult = Amazon.QLDB.Driver.IAsyncResult; ... IValueFactory valueFactory = new ValueFactory(); // Transforming a C# float to Ion. float nativeFloat = 256; IIonValue ionFloat = valueFactory.NewFloat(nativeFloat); IAsyncResult selectResult = await driver.Execute(async txn => { // Insertion into QLDB. await txn.Execute("UPDATE ExampleTable SET ExampleFloat = ?", ionFloat); // Fetching from QLDB. return await txn.Execute("SELECT VALUE ExampleFloat from ExampleTable"); }); float? retrievedFloat = null; // Assume there is only one document in ExampleTable. await foreach (IIonValue ionValue in selectResult) { // Transforming Ion to a C# float. We cast ionValue.DoubleValue to a float // but be cautious, this is a down-cast and can lose precision. retrievedFloat = (float)ionValue.DoubleValue; }
참고
동기 코드로 변환하려면
await
및async
키워드를 제거하고IAsyncResult
유형을IResult
로 변경하세요.C# 더블 사용
using IAsyncResult = Amazon.QLDB.Driver.IAsyncResult; ... IValueFactory valueFactory = new ValueFactory(); // Transforming a C# double to Ion. double nativeDouble = 256; IIonValue ionFloat = valueFactory.NewFloat(nativeDouble); IAsyncResult selectResult = await driver.Execute(async txn => { // Insertion into QLDB. await txn.Execute("UPDATE ExampleTable SET ExampleFloat = ?", ionFloat); // Fetching from QLDB. return await txn.Execute("SELECT VALUE ExampleFloat from ExampleTable"); }); double? retrievedDouble = null; // Assume there is only one document in ExampleTable. await foreach (IIonValue ionValue in selectResult) { // Transforming Ion to a C# double. retrievedDouble = ionValue.DoubleValue; }
참고
동기 코드로 변환하려면
await
및async
키워드를 제거하고IAsyncResult
유형을IResult
로 변경하세요. - Go
-
exampleFloat, err := driver.Execute(context.Background(), func(txn qldbdriver.Transaction) (interface{}, error) { aFloat := float32(256) // Insertion into QLDB _, err = txn.Execute("UPDATE ExampleTable SET ExampleFloat = ?", aFloat) if err != nil { return nil, err } // Fetching from QLDB result, err := txn.Execute("SELECT VALUE ExampleFloat FROM ExampleTable") if err != nil { return nil, err } // Assume there is only one document in ExampleTable if result.Next(txn) { // float64 would work as well var decodedResult float32 err := ion.Unmarshal(result.GetCurrentData(), &decodedResult) if err != nil { return nil, err } // exampleFloat is now the value fetched from QLDB return decodedResult, nil } return nil, result.Err() })
- Node.js
-
async function queryIonFloat(driver: QldbDriver): Promise<number> { return (driver.executeLambda(async (txn: TransactionExecutor) => { // Updating QLDB await txn.execute("UPDATE ExampleTable SET ExampleFloat = ?", 25.6); // Fetching from QLDB const resultList: dom.Value[] = (await txn.execute("SELECT VALUE ExampleFloat FROM ExampleTable")).getResultList(); // Assume there is only one document in ExampleTable const ionValue: dom.Value = resultList[0]; // Transforming Ion to a TypeScript Number const floatValue: number = ionValue.numberValue(); return floatValue; }) ); }
- Python
-
def update_and_query_ion_float(txn): # QLDB can take in a Python float a_float = float(256) # Insertion into QLDB txn.execute_statement("UPDATE ExampleTable SET ExampleFloat = ?", a_float) # Fetching from QLDB cursor = txn.execute_statement("SELECT VALUE ExampleFloat FROM ExampleTable") # Assume there is only one document in ExampleTable for ion_value in cursor: # Ion Python float is a child class of Python float a_float = ion_value # example_float is now the value fetched from QLDB return a_float example_float = driver.execute_lambda(lambda txn: update_and_query_ion_float(txn))
10진수
다음 코드 예에서는 Ion 10진수 타입을 처리하는 방법을 보여줍니다.
- Java
-
// Instantiate an IonSystem from the Ion library IonSystem ionSystem = IonSystemBuilder.standard().build(); double exampleDouble = driver.execute((txn) -> { // Transforming a Java double to Ion double aDouble = 256; IonValue ionDecimal = ionSystem.newDecimal(aDouble); // Insertion into QLDB txn.execute("UPDATE ExampleTable SET ExampleDecimal = ?", ionDecimal); // Fetching from QLDB Result result = txn.execute("SELECT VALUE ExampleDecimal from ExampleTable"); // Assume there is only one document in ExampleTable for (IonValue ionValue : result) { // Transforming Ion to a Java double // Cast IonValue to IonDecimal first aDouble = ((IonDecimal)ionValue).doubleValue(); } // exampleDouble is now the value fetched from QLDB return aDouble; });
- .NET
-
using IAsyncResult = Amazon.QLDB.Driver.IAsyncResult; ... IValueFactory valueFactory = new ValueFactory(); // Transforming a C# decimal to Ion. decimal nativeDecimal = 256.8723m; IIonValue ionDecimal = valueFactory.NewDecimal(nativeDecimal); IAsyncResult selectResult = await driver.Execute(async txn => { // Insertion into QLDB. await txn.Execute("UPDATE ExampleTable SET ExampleDecimal = ?", ionDecimal); // Fetching from QLDB. return await txn.Execute("SELECT VALUE ExampleDecimal from ExampleTable"); }); decimal? retrievedDecimal = null; // Assume there is only one document in ExampleTable. await foreach (IIonValue ionValue in selectResult) { // Transforming Ion to a C# decimal. retrievedDecimal = ionValue.DecimalValue; }
참고
동기 코드로 변환하려면
await
및async
키워드를 제거하고IAsyncResult
유형을IResult
로 변경하세요. - Go
-
exampleDecimal, err := driver.Execute(context.Background(), func(txn qldbdriver.Transaction) (interface{}, error) { aDecimal, err := ion.ParseDecimal("256") if err != nil { return nil, err } // Insertion into QLDB _, err = txn.Execute("UPDATE ExampleTable SET ExampleDecimal = ?", aDecimal) if err != nil { return nil, err } // Fetching from QLDB result, err := txn.Execute("SELECT VALUE ExampleDecimal FROM ExampleTable") if err != nil { return nil, err } // Assume there is only one document in ExampleTable if result.Next(txn) { var decodedResult ion.Decimal err := ion.Unmarshal(result.GetCurrentData(), &decodedResult) if err != nil { return nil, err } // exampleDecimal is now the value fetched from QLDB return decodedResult, nil } return nil, result.Err() })
- Node.js
-
async function queryIonDecimal(driver: QldbDriver): Promise<Decimal> { return (driver.executeLambda(async (txn: TransactionExecutor) => { // Creating a Decimal value. Decimal is an Ion Type with high precision let ionDecimal: Decimal = dom.load("2.5d-6").decimalValue(); // Updating QLDB await txn.execute("UPDATE ExampleTable SET ExampleDecimal = ?", ionDecimal); // Fetching from QLDB const resultList: dom.Value[] = (await txn.execute("SELECT VALUE ExampleDecimal FROM ExampleTable")).getResultList(); // Assume there is only one document in ExampleTable const ionValue: dom.Value = resultList[0]; // Get the Ion Decimal ionDecimal = ionValue.decimalValue(); return ionDecimal; }) ); }
참고
를 사용하여 Ion 십진수를 숫자로
ionValue.numberValue()
변환할 수도 있습니다. JavaScriptionValue.numberValue()
를 사용하면 성능이 더 좋지만 정확도는 떨어집니다. - Python
-
def update_and_query_ion_decimal(txn): # QLDB can take in a Python decimal a_decimal = Decimal(256) # Insertion into QLDB txn.execute_statement("UPDATE ExampleTable SET ExampleDecimal = ?", a_decimal) # Fetching from QLDB cursor = txn.execute_statement("SELECT VALUE ExampleDecimal FROM ExampleTable") # Assume there is only one document in ExampleTable for ion_value in cursor: # Ion Python decimal is a child class of Python decimal a_decimal = ion_value # example_decimal is now the value fetched from QLDB return a_decimal example_decimal = driver.execute_lambda(lambda txn: update_and_query_ion_decimal(txn))
Timestamp
다음 코드 예에서는 Ion 타임스탬프 타입을 처리하는 방법을 보여줍니다.
- Java
-
// Instantiate an IonSystem from the Ion library IonSystem ionSystem = IonSystemBuilder.standard().build(); Date exampleDate = driver.execute((txn) -> { // Transforming a Java Date to Ion Date aDate = new Date(); IonValue ionTimestamp = ionSystem.newUtcTimestamp(aDate); // Insertion into QLDB txn.execute("UPDATE ExampleTable SET ExampleTimestamp = ?", ionTimestamp); // Fetching from QLDB Result result = txn.execute("SELECT VALUE ExampleTimestamp from ExampleTable"); // Assume there is only one document in ExampleTable for (IonValue ionValue : result) { // Transforming Ion to a Java Date // Cast IonValue to IonTimestamp first aDate = ((IonTimestamp)ionValue).dateValue(); } // exampleDate is now the value fetched from QLDB return aDate; });
- .NET
-
using IAsyncResult = Amazon.QLDB.Driver.IAsyncResult; using Amazon.IonDotnet; ... IValueFactory valueFactory = new ValueFactory(); // Convert C# native DateTime to Ion. DateTime nativeDateTime = DateTime.Now; // First convert it to a timestamp object from Ion. Timestamp timestamp = new Timestamp(nativeDateTime); // Then convert to Ion timestamp. IIonValue ionTimestamp = valueFactory.NewTimestamp(timestamp); IAsyncResult selectResult = await driver.Execute(async txn => { // Insertion into QLDB. await txn.Execute("UPDATE ExampleTable SET ExampleTimestamp = ?", ionTimestamp); // Fetching from QLDB. return await txn.Execute("SELECT VALUE ExampleTimestamp from ExampleTable"); }); DateTime? retrievedDateTime = null; // Assume there is only one document in ExampleTable. await foreach (IIonValue ionValue in selectResult) { // Transforming Ion to a C# DateTime. retrievedDateTime = ionValue.TimestampValue.DateTimeValue; }
참고
동기 코드로 변환하려면
await
및async
키워드를 제거하고IAsyncResult
유형을IResult
로 변경하세요. - Go
-
exampleTimestamp, err := driver.Execute(context.Background(), func(txn qldbdriver.Transaction) (interface{}, error) { aTimestamp := time.Date(2006, time.May, 20, 12, 30, 0, 0, time.UTC) if err != nil { return nil, err } // Insertion into QLDB _, err = txn.Execute("UPDATE ExampleTable SET ExampleTimestamp = ?", aTimestamp) if err != nil { return nil, err } // Fetching from QLDB result, err := txn.Execute("SELECT VALUE ExampleTimestamp FROM ExampleTable") if err != nil { return nil, err } // Assume there is only one document in ExampleTable if result.Next(txn) { var decodedResult ion.Timestamp err := ion.Unmarshal(result.GetCurrentData(), &decodedResult) if err != nil { return nil, err } // exampleTimestamp is now the value fetched from QLDB return decodedResult.GetDateTime(), nil } return nil, result.Err() })
- Node.js
-
async function queryIonTimestamp(driver: QldbDriver): Promise<Date> { return (driver.executeLambda(async (txn: TransactionExecutor) => { let exampleDateTime: Date = new Date(Date.now()); // Updating QLDB await txn.execute("UPDATE ExampleTable SET ExampleTimestamp = ?", exampleDateTime); // Fetching from QLDB const resultList: dom.Value[] = (await txn.execute("SELECT VALUE ExampleTimestamp FROM ExampleTable")).getResultList(); // Assume there is only one document in ExampleTable const ionValue: dom.Value = resultList[0]; // Transforming Ion to a TypeScript Date exampleDateTime = ionValue.timestampValue().getDate(); return exampleDateTime; }) ); }
- Python
-
def update_and_query_ion_timestamp(txn): # QLDB can take in a Python timestamp a_datetime = datetime.now() # Insertion into QLDB txn.execute_statement("UPDATE ExampleTable SET ExampleTimestamp = ?", a_datetime) # Fetching from QLDB cursor = txn.execute_statement("SELECT VALUE ExampleTimestamp FROM ExampleTable") # Assume there is only one document in ExampleTable for ion_value in cursor: # Ion Python timestamp is a child class of Python datetime a_timestamp = ion_value # example_timestamp is now the value fetched from QLDB return a_timestamp example_timestamp = driver.execute_lambda(lambda txn: update_and_query_ion_timestamp(txn))
String
다음 코드 예에서는 Ion 문자열 타입을 처리하는 방법을 보여줍니다.
- Java
-
// Instantiate an IonSystem from the Ion library IonSystem ionSystem = IonSystemBuilder.standard().build(); String exampleString = driver.execute((txn) -> { // Transforming a Java String to Ion String aString = "Hello world!"; IonValue ionString = ionSystem.newString(aString); // Insertion into QLDB txn.execute("UPDATE ExampleTable SET ExampleString = ?", ionString); // Fetching from QLDB Result result = txn.execute("SELECT VALUE ExampleString from ExampleTable"); // Assume there is only one document in ExampleTable for (IonValue ionValue : result) { // Transforming Ion to a Java String // Cast IonValue to IonString first aString = ((IonString)ionValue).stringValue(); } // exampleString is now the value fetched from QLDB return aString; });
- .NET
-
using IAsyncResult = Amazon.QLDB.Driver.IAsyncResult; ... IValueFactory valueFactory = new ValueFactory(); // Convert C# string to Ion. String nativeString = "Hello world!"; IIonValue ionString = valueFactory.NewString(nativeString); IAsyncResult selectResult = await driver.Execute(async txn => { // Insertion into QLDB. await txn.Execute("UPDATE ExampleTable SET ExampleString = ?", ionString); // Fetching from QLDB. return await txn.Execute("SELECT VALUE ExampleString from ExampleTable"); }); String retrievedString = null; // Assume there is only one document in ExampleTable. await foreach (IIonValue ionValue in selectResult) { // Transforming Ion to a C# string. retrievedString = ionValue.StringValue; }
참고
동기 코드로 변환하려면
await
및async
키워드를 제거하고IAsyncResult
유형을IResult
로 변경하세요. - Go
-
exampleString, err := driver.Execute(context.Background(), func(txn qldbdriver.Transaction) (interface{}, error) { aString := "Hello World!" // Insertion into QLDB _, err = txn.Execute("UPDATE ExampleTable SET ExampleString = ?", aString) if err != nil { return nil, err } // Fetching from QLDB result, err := txn.Execute("SELECT VALUE ExampleString FROM ExampleTable") if err != nil { return nil, err } // Assume there is only one document in ExampleTable if result.Next(txn) { var decodedResult string err := ion.Unmarshal(result.GetCurrentData(), &decodedResult) if err != nil { return nil, err } // exampleString is now the value fetched from QLDB return decodedResult, nil } return nil, result.Err() })
- Node.js
-
async function queryIonString(driver: QldbDriver): Promise<string> { return (driver.executeLambda(async (txn: TransactionExecutor) => { // Updating QLDB await txn.execute("UPDATE ExampleTable SET ExampleString = ?", "Hello World!"); // Fetching from QLDB const resultList: dom.Value[] = (await txn.execute("SELECT VALUE ExampleString FROM ExampleTable")).getResultList(); // Assume there is only one document in ExampleTable const ionValue: dom.Value = resultList[0]; // Transforming Ion to a TypeScript String const stringValue: string = ionValue.stringValue(); return stringValue; }) ); }
- Python
-
def update_and_query_ion_string(txn): # QLDB can take in a Python string a_string = "Hello world!" # Insertion into QLDB txn.execute_statement("UPDATE ExampleTable SET ExampleString = ?", a_string) # Fetching from QLDB cursor = txn.execute_statement("SELECT VALUE ExampleString FROM ExampleTable") # Assume there is only one document in ExampleTable for ion_value in cursor: # Ion Python string is a child class of Python string a_string = ion_value # example_string is now the value fetched from QLDB return a_string example_string = driver.execute_lambda(lambda txn: update_and_query_ion_string(txn))
Blob
다음 코드 예에서는 Ion blob 타입을 처리하는 방법을 보여줍니다.
- Java
-
// Instantiate an IonSystem from the Ion library IonSystem ionSystem = IonSystemBuilder.standard().build(); byte[] exampleBytes = driver.execute((txn) -> { // Transforming a Java byte array to Ion // Transform any arbitrary data to a byte array to store in QLDB String aString = "Hello world!"; byte[] aByteArray = aString.getBytes(); IonValue ionBlob = ionSystem.newBlob(aByteArray); // Insertion into QLDB txn.execute("UPDATE ExampleTable SET ExampleBlob = ?", ionBlob); // Fetching from QLDB Result result = txn.execute("SELECT VALUE ExampleBlob from ExampleTable"); // Assume there is only one document in ExampleTable for (IonValue ionValue : result) { // Transforming Ion to a Java byte array // Cast IonValue to IonBlob first aByteArray = ((IonBlob)ionValue).getBytes(); } // exampleBytes is now the value fetched from QLDB return aByteArray; });
- .NET
-
using IAsyncResult = Amazon.QLDB.Driver.IAsyncResult; using System.Text; ... IValueFactory valueFactory = new ValueFactory(); // Transform any arbitrary data to a byte array to store in QLDB. string nativeString = "Hello world!"; byte[] nativeByteArray = Encoding.UTF8.GetBytes(nativeString); // Transforming a C# byte array to Ion. IIonValue ionBlob = valueFactory.NewBlob(nativeByteArray); IAsyncResult selectResult = await driver.Execute(async txn => { // Insertion into QLDB. await txn.Execute("UPDATE ExampleTable SET ExampleBlob = ?", ionBlob); // Fetching from QLDB. return await txn.Execute("SELECT VALUE ExampleBlob from ExampleTable"); }); byte[] retrievedByteArray = null; // Assume there is only one document in ExampleTable. await foreach (IIonValue ionValue in selectResult) { // Transforming Ion to a C# byte array. retrievedByteArray = ionValue.Bytes().ToArray(); }
참고
동기 코드로 변환하려면
await
및async
키워드를 제거하고IAsyncResult
유형을IResult
로 변경하세요. - Go
-
exampleBlob, err := driver.Execute(context.Background(), func(txn qldbdriver.Transaction) (interface{}, error) { aBlob := []byte("Hello World!") // Insertion into QLDB _, err = txn.Execute("UPDATE ExampleTable SET ExampleBlob = ?", aBlob) if err != nil { return nil, err } // Fetching from QLDB result, err := txn.Execute("SELECT VALUE ExampleBlob FROM ExampleTable") if err != nil { return nil, err } // Assume there is only one document in ExampleTable if result.Next(txn) { var decodedResult []byte err := ion.Unmarshal(result.GetCurrentData(), &decodedResult) if err != nil { return nil, err } // exampleBlob is now the value fetched from QLDB return decodedResult, nil } return nil, result.Err() })
- Node.js
-
async function queryIonBlob(driver: QldbDriver): Promise<Uint8Array> { return (driver.executeLambda(async (txn: TransactionExecutor) => { const enc = new TextEncoder(); let blobValue: Uint8Array = enc.encode("Hello World!"); // Updating QLDB await txn.execute("UPDATE ExampleTable SET ExampleBlob = ?", blobValue); // Fetching from QLDB const resultList: dom.Value[] = (await txn.execute("SELECT VALUE ExampleBlob FROM ExampleTable")).getResultList(); // Assume there is only one document in ExampleTable const ionValue: dom.Value = resultList[0]; // Transforming Ion to TypeScript Uint8Array blobValue = ionValue.uInt8ArrayValue(); return blobValue; }) ); }
- Python
-
def update_and_query_ion_blob(txn): # QLDB can take in a Python byte array a_string = "Hello world!" a_byte_array = str.encode(a_string) # Insertion into QLDB txn.execute_statement("UPDATE ExampleTable SET ExampleBlob = ?", a_byte_array) # Fetching from QLDB cursor = txn.execute_statement("SELECT VALUE ExampleBlob FROM ExampleTable") # Assume there is only one document in ExampleTable for ion_value in cursor: # Ion Python blob is a child class of Python byte array a_blob = ion_value # example_blob is now the value fetched from QLDB return a_blob example_blob = driver.execute_lambda(lambda txn: update_and_query_ion_blob(txn))
나열
다음 코드 예는 Ion 리스트 타입을 처리하는 방법을 보여줍니다.
- Java
-
// Instantiate an IonSystem from the Ion library IonSystem ionSystem = IonSystemBuilder.standard().build(); List<Integer> exampleList = driver.execute((txn) -> { // Transforming a Java List to Ion List<Integer> aList = new ArrayList<>(); // Add 5 Integers to the List for the sake of example for (int i = 0; i < 5; i++) { aList.add(i); } // Create an empty Ion List IonList ionList = ionSystem.newEmptyList(); // Add the 5 Integers to the Ion List for (Integer i : aList) { // Convert each Integer to Ion ints first to add it to the Ion List ionList.add(ionSystem.newInt(i)); } // Insertion into QLDB txn.execute("UPDATE ExampleTable SET ExampleList = ?", (IonValue) ionList); // Fetching from QLDB Result result = txn.execute("SELECT VALUE ExampleList from ExampleTable"); // Assume there is only one document in ExampleTable for (IonValue ionValue : result) { // Iterate through the Ion List to map it to a Java List List<Integer> intList = new ArrayList<>(); for (IonValue ionInt : (IonList)ionValue) { // Convert the 5 Ion ints to Java Integers intList.add(((IonInt)ionInt).intValue()); } aList = intList; } // exampleList is now the value fetched from QLDB return aList; });
- .NET
-
using IAsyncResult = Amazon.QLDB.Driver.IAsyncResult; using System.Collections.Generic; ... IValueFactory valueFactory = new ValueFactory(); // Transforming a C# list to Ion. IIonValue ionList = valueFactory.NewEmptyList(); foreach (int i in new List<int> {0, 1, 2, 3, 4}) { // Convert to Ion int and add to Ion list. ionList.Add(valueFactory.NewInt(i)); } IAsyncResult selectResult = await driver.Execute(async txn => { // Insertion into QLDB. await txn.Execute("UPDATE ExampleTable SET ExampleList = ?", ionList); // Fetching from QLDB. return await txn.Execute("SELECT VALUE ExampleList from ExampleTable"); }); List<int> retrievedList = new List<int>(); await foreach (IIonValue ionValue in selectResult) { // Iterate through the Ion List to map it to a C# list. foreach (IIonValue ionInt in ionValue) { retrievedList.Add(ionInt.IntValue); } }
참고
동기 코드로 변환하려면
await
및async
키워드를 제거하고IAsyncResult
유형을IResult
로 변경하세요. - Go
-
exampleList, err := driver.Execute(context.Background(), func(txn qldbdriver.Transaction) (interface{}, error) { aList := []int{1, 2, 3, 4, 5} // Insertion into QLDB _, err = txn.Execute("UPDATE ExampleTable SET ExampleList = ?", aList) if err != nil { return nil, err } // Fetching from QLDB result, err := txn.Execute("SELECT VALUE ExampleList FROM ExampleTable") if err != nil { return nil, err } // Assume there is only one document in ExampleTable if result.Next(txn) { var decodedResult []int err := ion.Unmarshal(result.GetCurrentData(), &decodedResult) if err != nil { return nil, err } // exampleList is now the value fetched from QLDB return decodedResult, nil } return nil, result.Err() })
- Node.js
-
async function queryIonList(driver: QldbDriver): Promise<number[]> { return (driver.executeLambda(async (txn: TransactionExecutor) => { let listOfNumbers: number[] = [1, 2, 3, 4, 5]; // Updating QLDB await txn.execute("UPDATE ExampleTable SET ExampleList = ?", listOfNumbers); // Fetching from QLDB const resultList: dom.Value[] = (await txn.execute("SELECT VALUE ExampleList FROM ExampleTable")).getResultList(); // Assume there is only one document in ExampleTable const ionValue: dom.Value = resultList[0]; // Get Ion List const ionList: dom.Value[] = ionValue.elements(); // Iterate through the Ion List to map it to a JavaScript Array let intList: number[] = []; ionList.forEach(item => { // Transforming Ion to a TypeScript Number const intValue: number = item.numberValue(); intList.push(intValue); }); listOfNumbers = intList; return listOfNumbers; }) ); }
- Python
-
def update_and_query_ion_list(txn): # QLDB can take in a Python list a_list = list() for i in range(0, 5): a_list.append(i) # Insertion into QLDB txn.execute_statement("UPDATE ExampleTable SET ExampleList = ?", a_list) # Fetching from QLDB cursor = txn.execute_statement("SELECT VALUE ExampleList FROM ExampleTable") # Assume there is only one document in ExampleTable for ion_value in cursor: # Ion Python blob is a child class of Python list a_list = ion_value # example_list is now the value fetched from QLDB return a_list example_list = driver.execute_lambda(lambda txn: update_and_query_ion_list(txn))
구조체
에서 QLDB struct
데이터 유형은 다른 Ion 유형과 특히 다릅니다. 표에 삽입하는 최상위 문서는 struct
타입이어야 합니다. 문서 필드는 중첩된 struct
를 저장할 수도 있습니다.
단순화를 위해 다음 예에서는 ExampleString
및 ExampleInt
필드만 있는 문서를 정의합니다.
- Java
-
class ExampleStruct { public String exampleString; public int exampleInt; public ExampleStruct(String exampleString, int exampleInt) { this.exampleString = exampleString; this.exampleInt = exampleInt; } } // Instantiate an IonSystem from the Ion library IonSystem ionSystem = IonSystemBuilder.standard().build(); ExampleStruct examplePojo = driver.execute((txn) -> { // Transforming a POJO to Ion ExampleStruct aPojo = new ExampleStruct("Hello world!", 256); // Create an empty Ion struct IonStruct ionStruct = ionSystem.newEmptyStruct(); // Map the fields of the POJO to Ion values and put them in the Ion struct ionStruct.add("ExampleString", ionSystem.newString(aPojo.exampleString)); ionStruct.add("ExampleInt", ionSystem.newInt(aPojo.exampleInt)); // Insertion into QLDB txn.execute("INSERT INTO ExampleTable ?", ionStruct); // Fetching from QLDB Result result = txn.execute("SELECT * from ExampleTable"); // Assume there is only one document in ExampleTable for (IonValue ionValue : result) { // Map the fields of the Ion struct to Java values and construct a new POJO ionStruct = (IonStruct)ionValue; IonString exampleString = (IonString)ionStruct.get("ExampleString"); IonInt exampleInt = (IonInt)ionStruct.get("ExampleInt"); aPojo = new ExampleStruct(exampleString.stringValue(), exampleInt.intValue()); } // examplePojo is now the document fetched from QLDB return aPojo; });
또는 Jackson 라이브러리
를 사용하여 Ion에 데이터 타입을 매핑하거나 Ion에서 데이터 타입을 매핑할 수 있습니다. 라이브러리는 다른 Ion 데이터 타입을 지원하지만 이 예에서는 struct
타입에 초점을 맞춥니다.class ExampleStruct { public String exampleString; public int exampleInt; @JsonCreator public ExampleStruct(@JsonProperty("ExampleString") String exampleString, @JsonProperty("ExampleInt") int exampleInt) { this.exampleString = exampleString; this.exampleInt = exampleInt; } @JsonProperty("ExampleString") public String getExampleString() { return this.exampleString; } @JsonProperty("ExampleInt") public int getExampleInt() { return this.exampleInt; } } // Instantiate an IonSystem from the Ion library IonSystem ionSystem = IonSystemBuilder.standard().build(); // Instantiate an IonObjectMapper from the Jackson library IonObjectMapper ionMapper = new IonValueMapper(ionSystem); ExampleStruct examplePojo = driver.execute((txn) -> { // Transforming a POJO to Ion ExampleStruct aPojo = new ExampleStruct("Hello world!", 256); IonValue ionStruct; try { // Use the mapper to convert Java objects into Ion ionStruct = ionMapper.writeValueAsIonValue(aPojo); } catch (IOException e) { // Wrap the exception and throw it for the sake of simplicity in this example throw new RuntimeException(e); } // Insertion into QLDB txn.execute("INSERT INTO ExampleTable ?", ionStruct); // Fetching from QLDB Result result = txn.execute("SELECT * from ExampleTable"); // Assume there is only one document in ExampleTable for (IonValue ionValue : result) { // Use the mapper to convert Ion to Java objects try { aPojo = ionMapper.readValue(ionValue, ExampleStruct.class); } catch (IOException e) { // Wrap the exception and throw it for the sake of simplicity in this example throw new RuntimeException(e); } } // examplePojo is now the document fetched from QLDB return aPojo; });
- .NET
-
아마존을 이용하세요. QLDB.Driver.Serialization
라이브러리를 사용하여 네이티브 C# 데이터 유형을 Ion과 매핑하거나 Ion으로부터 네이티브 데이터 유형을 매핑할 수 있습니다. 라이브러리는 다른 Ion 데이터 타입을 지원하지만 이 예에서는 struct
타입에 초점을 맞춥니다.using Amazon.QLDB.Driver.Generic; using Amazon.QLDB.Driver.Serialization; ... IAsyncQldbDriver driver = AsyncQldbDriver.Builder() .WithLedger("vehicle-registration") // Add Serialization library .WithSerializer(new ObjectSerializer()) .Build(); // Creating a C# POCO. ExampleStruct exampleStruct = new ExampleStruct { ExampleString = "Hello world!", ExampleInt = 256 }; IAsyncResult<ExampleStruct> selectResult = await driver.Execute(async txn => { // Insertion into QLDB. await txn.Execute(txn.Query<Document>("UPDATE ExampleTable SET ExampleStruct = ?", exampleStruct)); // Fetching from QLDB. return await txn.Execute(txn.Query<ExampleStruct>("SELECT VALUE ExampleStruct from ExampleTable")); }); await foreach (ExampleStruct row in selectResult) { Console.WriteLine(row.ExampleString); Console.WriteLine(row.ExampleInt); }
참고
동기 코드로 변환하려면
await
및async
키워드를 제거하고IAsyncResult
유형을IResult
로 변경하세요.또는 Amazon을 사용할 수도 있습니다. IonDotnet.Builders
라이브러리는 Ion 데이터 유형을 처리합니다. using IAsyncResult = Amazon.QLDB.Driver.IAsyncResult; ... IValueFactory valueFactory = new ValueFactory(); // Creating Ion struct. IIonValue ionStruct = valueFactory.NewEmptyStruct(); ionStruct.SetField("ExampleString", valueFactory.NewString("Hello world!")); ionStruct.SetField("ExampleInt", valueFactory.NewInt(256)); IAsyncResult selectResult = await driver.Execute(async txn => { // Insertion into QLDB. await txn.Execute("UPDATE ExampleTable SET ExampleStruct = ?", ionStruct); // Fetching from QLDB. return await txn.Execute("SELECT VALUE ExampleStruct from ExampleTable"); }); string retrievedString = null; int? retrievedInt = null; await foreach (IIonValue ionValue in selectResult) { retrievedString = ionValue.GetField("ExampleString").StringValue; retrievedInt = ionValue.GetField("ExampleInt").IntValue; }
- Go
-
exampleStruct, err := driver.Execute(context.Background(), func(txn qldbdriver.Transaction) (interface{}, error) { aStruct := map[string]interface{} { "ExampleString": "Hello World!", "ExampleInt": 256, } // Insertion into QLDB _, err = txn.Execute("UPDATE ExampleTable SET ExampleStruct = ?", aStruct) if err != nil { return nil, err } // Fetching from QLDB result, err := txn.Execute("SELECT VALUE ExampleStruct FROM ExampleTable") if err != nil { return nil, err } // Assume there is only one document in ExampleTable if result.Next(txn) { var decodedResult map[string]interface{} err := ion.Unmarshal(result.GetCurrentData(), &decodedResult) if err != nil { return nil, err } // exampleStruct is now the value fetched from QLDB return decodedResult, nil } return nil, result.Err() })
- Node.js
-
async function queryIonStruct(driver: QldbDriver): Promise<any> { let exampleStruct: any = {stringValue: "Hello World!", intValue: 256}; return (driver.executeLambda(async (txn: TransactionExecutor) => { // Inserting into QLDB await txn.execute("INSERT INTO ExampleTable ?", exampleStruct); // Fetching from QLDB const resultList: dom.Value[] = (await txn.execute("SELECT * FROM ExampleTable")).getResultList(); // Assume there is only one document in ExampleTable const ionValue: dom.Value = resultList[0]; // We can get all the keys of Ion struct and their associated values const ionFieldNames: string[] = ionValue.fieldNames(); // Getting key and value of Ion struct to TypeScript String and Number const nativeStringVal: string = ionValue.get(ionFieldNames[0]).stringValue(); const nativeIntVal: number = ionValue.get(ionFieldNames[1]).numberValue(); // Alternatively, we can access to Ion struct fields, using their literal field names: // const nativeStringVal = ionValue.get("stringValue").stringValue(); // const nativeIntVal = ionValue.get("intValue").numberValue(); exampleStruct = {[ionFieldNames[0]]: nativeStringVal, [ionFieldNames[1]]: nativeIntVal}; return exampleStruct; }) ); }
- Python
-
def update_and_query_ion_struct(txn): # QLDB can take in a Python struct a_struct = {"ExampleString": "Hello world!", "ExampleInt": 256} # Insertion into QLDB txn.execute_statement("UPDATE ExampleTable SET ExampleStruct = ?", a_struct) # Fetching from QLDB cursor = txn.execute_statement("SELECT VALUE ExampleStruct FROM ExampleTable") # Assume there is only one document in ExampleTable for ion_value in cursor: # Ion Python struct is a child class of Python struct a_struct = ion_value # example_struct is now the value fetched from QLDB return a_struct example_struct = driver.execute_lambda(lambda txn: update_and_query_ion_struct(txn))
Null 값 및 동적 타입
QLDB공개 콘텐츠를 지원하며 문서 필드에 대한 스키마 또는 데이터 유형 정의를 적용하지 않습니다. 문서에 Ion null 값을 저장할 수도 있습니다. QLDB 위의 모든 예에서는 반환된 각 데이터 타입이 알려져 있고 null이 아니라고 가정합니다. 다음 예에서는 데이터 타입을 알 수 없거나 null일 가능성이 있는 경우 Ion을 사용하는 방법을 보여줍니다.
- Java
-
// Empty variables String exampleString = null; Integer exampleInt = null; // Assume ionValue is some queried data from QLDB IonValue ionValue = null; // Check the value type and assign it to the variable if it is not null if (ionValue.getType() == IonType.STRING) { if (ionValue.isNullValue()) { exampleString = null; } else { exampleString = ((IonString)ionValue).stringValue(); } } else if (ionValue.getType() == IonType.INT) { if (ionValue.isNullValue()) { exampleInt = null; } else { exampleInt = ((IonInt)ionValue).intValue(); } }; // Creating null values IonSystem ionSystem = IonSystemBuilder.standard().build(); // A null value still has an Ion type IonString ionString; if (exampleString == null) { // Specifically a null string ionString = ionSystem.newNullString(); } else { ionString = ionSystem.newString(exampleString); } IonInt ionInt; if (exampleInt == null) { // Specifically a null int ionInt = ionSystem.newNullInt(); } else { ionInt = ionSystem.newInt(exampleInt); } // Special case regarding null! // There is a generic null type which has Ion type 'Null'. // The above null values still have the types 'String' and 'Int' IonValue specialNull = ionSystem.newNull(); if (specialNull.getType() == IonType.NULL) { // This is true! } if (specialNull.isNullValue()) { // This is also true! } if (specialNull.getType() == IonType.STRING || specialNull.getType() == IonType.INT) { // This is false! }
- .NET
-
// Empty variables. string exampleString = null; int? exampleInt = null; // Assume ionValue is some queried data from QLDB. IIonValue ionValue; if (ionValue.Type() == IonType.String) { exampleString = ionValue.StringValue; } else if (ionValue.Type() == IonType.Int) { if (ionValue.IsNull) { exampleInt = null; } else { exampleInt = ionValue.IntValue; } }; // Creating null values. IValueFactory valueFactory = new ValueFactory(); // A null value still has an Ion type. IIonValue ionString = valueFactory.NewString(exampleString); IIonValue ionInt; if (exampleInt == null) { // Specifically a null int. ionInt = valueFactory.NewNullInt(); } else { ionInt = valueFactory.NewInt(exampleInt.Value); } // Special case regarding null! // There is a generic null type which has Ion type 'Null'. IIonValue specialNull = valueFactory.NewNull(); if (specialNull.Type() == IonType.Null) { // This is true! } if (specialNull.IsNull) { // This is also true! }
- Go
-
수렴 제한
Go에서
nil
값을 수렴한 다음 수렴 취소하면 해당 값의 타입이 유지되지 않습니다.nil
값은 Ion null로 수렴되지만, Ion null은nil
이 아닌 값 0으로 수렴 취소됩니다.ionNull, err := ion.MarshalText(nil) // ionNull is set to ion null if err != nil { return } var result int err = ion.Unmarshal(ionNull, &result) // result unmarshals to 0 if err != nil { return }
- Node.js
-
// Empty variables let exampleString: string; let exampleInt: number; // Assume ionValue is some queried data from QLDB // Check the value type and assign it to the variable if it is not null if (ionValue.getType() === IonTypes.STRING) { if (ionValue.isNull()) { exampleString = null; } else { exampleString = ionValue.stringValue(); } } else if (ionValue.getType() === IonTypes.INT) { if (ionValue.isNull()) { exampleInt = null; } else { exampleInt = ionValue.numberValue(); } } // Creating null values if (exampleString === null) { ionString = dom.load('null.string'); } else { ionString = dom.load.of(exampleString); } if (exampleInt === null) { ionInt = dom.load('null.int'); } else { ionInt = dom.load.of(exampleInt); } // Special case regarding null! // There is a generic null type which has Ion type 'Null'. // The above null values still have the types 'String' and 'Int' specialNull: dom.Value = dom.load("null.null"); if (specialNull.getType() === IonType.NULL) { // This is true! } if (specialNull.getType() === IonType.STRING || specialNull.getType() === IonType.INT) { // This is false! }
- Python
-
# Empty variables example_string = None example_int = None # Assume ion_value is some queried data from QLDB # Check the value type and assign it to the variable if it is not null if ion_value.ion_type == IonType.STRING: if isinstance(ion_value, IonPyNull): example_string = None else: example_string = ion_value elif ion_value.ion_type == IonType.INT: if isinstance(ion_value, IonPyNull): example_int = None else: example_int = ion_value # Creating Ion null values if example_string is None: # Specifically a null string ion_string = loads("null.string") else: # QLDB can take in Python string ion_string = example_string if example_int is None: # Specifically a null int ion_int = loads("null.int") else: # QLDB can take in Python int ion_int = example_int # Special case regarding null! # There is a generic null type which has Ion type 'Null'. # The above null values still have the types 'String' and 'Int' special_null = loads("null.null") if special_null.ion_type == IonType.NULL: # This is true! if special_null.ion_type == IonType.STRING or special_null.ion_type == IonType.INT: # This is false!
로 하향 변환 JSON
애플리케이션에 JSON 호환성이 필요한 경우 Amazon Ion 데이터를 로 하향 변환할 수 있습니다. JSON 그러나 데이터에 존재하지 않는 풍부한 이온 유형을 사용하는 경우 Ion을 변환해도 손실이 발생합니다. JSON JSON
Ion으로의 JSON 변환 규칙에 대한 자세한 내용은 Amazon Ion JSON 쿡북의 하향 변환을